In the prior art, the keyboard carrier includes a base for fixedly connecting to an underside of a desk, a slide seat slidably mounted between two sliding rails formed below two lateral edges of the base, a bracket mount connected to an underside of the slide seat, a pair of links and an elevating member pivotally connected at respective rear ends to two front ends of the bracket mount to form a link mechanism for adjusting a height of front ends of the links and the elevating member relative to the desk, and an inclining member pivotally connected at two rear ends to two front ends of the elevating member via a long shaft of a quick-detachable mechanism located below the inclining member. The long shaft is extended through two curved slots formed at the front ends of the elevating member and thereby allows the inclining member to slide in the curved slots for adjusting an inclination of the inclining member relative to the desk.
Since the quick-detachable mechanism is provided at pivoting points between the elevating member and the two links, as well as the pivoting points between the inclining member and the elevating member, locking of the quick-detachable mechanism in place would also lock the pivoting points on the link mechanism formed from the elevating member and the links, as well as the pivoting points between the elevating and the inclining member, causing the keyboard carrier to be locked to the adjusted elevation and inclination at the same time.
The quick-detachable mechanism includes a long shaft disposed in a quick detachable sleeve. When the long shaft is tightened, the links, the elevating member, and the inclining member are brought to closely contact with one another at the pivotally connected positions, so that the pivoting points become immovable to achieve the locating effect. However, the above-described quick-detachable mechanism provides only a very limited supporting force. When an excessive force is applied on the keyboard carrier, or the keyboard carrier has been used over a prolonged time, the quick-detachable mechanism tends to become loose from the keyboard carrier and fails to stably support the keyboard carrier.